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Naveed Akhtar

Publications and source records attributed to Naveed Akhtar.

14 recordsLinked to original sources
PubMed2006

Clinical deterioration after intravenous recombinant tissue plasminogen activator treatment: a multicenter transcranial Doppler study.

BACKGROUND AND PURPOSE: Patients may experience clinical deterioration (CD) after treatment with intravenous recombinant tissue plasminogen activator (rt-PA). We evaluated the ability of flow findings on transcranial Doppler to predict CD and outcomes on modified Rankin Scale. METHODS: Patients with acute stroke received intravenous rt-PA within 3 hours of symptom onset at four academic centers. CD was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) score by 4 points or more within 24 hours. Poor long-term outcome was defined by modified Rankin Scale > or =2 at 3 months. Transcranial Doppler findings were interpreted using the Thrombolysis in Brain Ischemia flow grading system as persistent arterial occlusion, reocclusion, or complete recanalization. Multiple regression analysis was used to identify transcranial Doppler flow as a predictor for CD after controlling for age, sex, baseline NIHSS, hypertension, and glucose. RESULTS: A total of 374 patients received intravenous rt-PA at 142+/-60 minutes (median pretreatment NIHSS score 16 points). At the end of intravenous rt-PA infusion, transcranial Doppler showed persistent arterial occlusion in 219 patients (59%), arterial reocclusion in 54 patients (14%), and complete recanalization in 101 patients (27%). CD occurred in 44 patients: 36 had persistent arterial occlusion or reocclusion (82%), 13 symptomatic intracerebral hemorrhage (29%), and both persistent occlusion/reocclusion and symptomatic intracerebral hemorrhage in 10 patients (23%). After adjustment, patient risk for CD with persistent occlusion was OR 1.7 (95% CI: 0.7 to 4) and with arterial reocclusion 4.9 (95% CI: 1.7 to 13) (P=0.002). Patient risk for poor long-term outcomes with persistent occlusion, partial recanalization, or reocclusion was OR 5.2 (95% CI: 2.7 to 9, P=0.001). CONCLUSIONS: Inability to achieve or sustain vessel patency at the end of rt-PA infusion correlates with the likelihood of clinical deterioration and poor long-term outcome. Early arterial reocclusion on transcranial Doppler is highly predictive of CD and poor outcome.

Adult↗
PubMed2006

Segmental left ventricular wall motion abnormalities are associated with lacunar ischemic stroke.

OBJECTIVE: The aim of this study was to determine whether segmental left ventricular wall motion abnormalities (SLVWMA) are a potential cause of ischemic stroke. METHODS: Demographics, cardiovascular risk factors and echocardiographic parameters of patients with ischemic stroke (with and without SLVWMA) were collected and compared with those of patients who had SLVWMA but without history of ischemic stroke. RESULTS: Two hundred and fifty nine patients with ischemic stroke were identified: 187 patients without SLVWMA, and 72 with SLVWMA. The cardiac group consisted of 79 patients. Compared with the stroke patients with SLVWMA, stroke patients without SLVWMA were slightly but significantly younger (59 versus 63 years of age). Furthermore, the number of risk factors in stroke patients without SLVWMA was significantly lower compared with stroke patients with SLVWMA (2.7 versus 3.7). There was no difference in age or gender between stroke patients with SLVWMA and the cardiac patients. However, the number of risk factors was significantly higher in the cardiac patients compared with stroke patients with SLVWMA (4.4 versus 3.7). The ejection fraction was normal in both groups of stroke patients but significantly lower in the cardiac patients (37%). Significantly more lacunar ischemic strokes were observed in stroke patients with SLVWMA than in those without SLVWMA (76% versus 68%). CONCLUSION: Our data indicate that in ischemic stroke patients with multiple cardiovascular risk factors and SLVWMA a higher frequency of lacunar strokes can be found. The latter could be a marker of small-vessel disease and/or be a potential contributing factor, perhaps through a mechanism of cardiac microembolism, in the development of lacunar ischemic stroke. The mechanisms of the association between SLVWMA and lacunar ischemic stroke remain however unclear.

Adult↗
PubMed2006

The relationship between diffusion anisotropy and time of onset after stroke.

Diffusion anisotropy changes in stroke lesions less than 24 h after onset have been reported to be elevated, decreased, or both. To address these mixed findings, we sought to characterize temporal changes of diffusion anisotropy by analyzing anatomically distinct ischemic white matter (WM) regions at 3 time phases within the first 34 h of ischemic stroke onset in 26 stroke patients (2 to 5 h, N=7; 7 to 14 h, N=11; 18 to 34 h, N=8). Mean diffusivity (Trace/3 apparent diffusion coefficient (ADC)), fractional anisotropy (FA), and T2-weighted signal intensity were measured for major and subcortical WM in lesions defined by a >or=30% drop in Trace/3 ADC. Major WM tract lesions with mean decreases of approximately 40% in relative (r) Trace/3 ADC showed an increased rFA of 1.11+/-0.18 (P<0.01) during the hyperacute phase (2 to 5 h), whereas rFA declined to 0.90+/-0.20 (P<0.01) and 0.88+/-0.12 (P<0.01) in the acute (7 to 14 h) and subacute (18 to 34 h) phases, respectively. Of those patients with lesions in major WM, 4 of 8 patients <or=7 h showed elevated rFA as opposed to none of the remaining 13 patients after 7 h. A greater proportion of the evaluated WM regions-of-interest (ROI) in the hyperacute phase revealed increases in rFA (60%), whereas conversely large proportions of ROIs (55% and 59%) in the acute and subacute phases showed reduced rFA. Similar anisotropy changes were noted in subcortical WM regions in the gyri.

Adult↗
PubMed2006

Haematologic disorders and cerebral venous thrombosis.

This review focuses on the several coagulation disorders (the so called hypercoagulable states) that are associated with cerebral venous thrombosis. Hypercoagulable states likely explain the high percentage of cases of cryptogenic cerebral infarction in young people. The most common of the hereditary defects appear to be deficiency of antithrombin III, protein C or protein S, activated protein C resistance and prothrombin 20211A mutation. In a large majority of cases activated protein C resistance is due to the presence of factor V Leiden. Antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies) represent an acquired disorder of coagulation. Rare defects include heparin cofactor II (HC II), plasminogen or tissue plasminogen activator deficiency (TPA), elevated plasminogen activator inhibitor-1 (PAI-1) and dysfibrinogenemia. Hyperhomocystinemia is responsible for both arterial and venous thrombosis. A work-up to identify one of the recognizable hypercoagulable states is indicated, especially in younger patients with stroke. Laboratory evaluation for hypercoagulable states may also often be indicated in those patients who do not have other obvious risk factors for their stroke. If from clinical history, family history and/or laboratory studies, a patient is felt to have a hypercoagulable state, the decision for long term chronic anticoagulation needs to be individualized. If a hereditary hypercoagulable state is found, it also may be appropriate to recommend screening of other family members.

Antiphospholipid Syndrome↗
PubMed2005

Rheumatic mitral stenosis presenting as acute abdominal aortic occlusion and foot drop.

Systemic thromboembolism in not an infrequent complication of rheumatic mitral stenosis. We report a case of acute abdominal aortic occlusion due to rheumatic mitral stenosis, in the absence of atrial fibrillation, mimicking spinal cord compression. Systemic streptokinase given 48 hours after symptom's onset lead to rapid and dramatic recovery with limb salvage.

Aorta, Abdominal↗
PubMed2004

Association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and essential hypertension in young Pakistani patients.

Several studies have demonstrated the importance of angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphisms in the pathogenesis of hypertension. This study sought to determine the association between the ACE I/D polymorphism and essential hypertension in young Pakistanis. The frequency of the ACE I/D polymorphism was established by a comparative cross-sectional survey of Pakistani patients suffering from essential hypertension and ethnically matched normotensive controls. Samples were collected from tertiary care hospitals in northern Pakistan. Hypertensive individuals were defined as those with a systolic blood pressure > 140 mmHg and/or diastolic blood pressure > 90 mmHg on three separate occasions, or those currently receiving one, or more, anti-hypertensive agents. DNA samples obtained from hypertensive (n = 211) and normotensive (n = 108) individuals were typed by PCR. The frequency of the ACE I/I genotype was significantly higher in hypertensive patients, aged 20-40 years, than in normotensive controls of the same age group (chi(2) = 4.0, P = 0.041). Whereas no overall significant differences were observed between the I/I, I/D and D/D ACE genotypes (One way ANOVA, F = 0.672; P = 0.413). The association between the ACE I/I genotype and essential hypertension in individuals aged </= 40 years suggests that ACE has a role in early onset essential hypertension in Pakistan.

Adult↗
PubMed2004

Current and future concepts in stroke prevention.

Stroke is a major cause of morbidity and mortality in an aging population. The current understanding of the pathophysiology of atherosclerotic diseases, the most common cause of stroke, and the evidence for existing therapeutic interventions for the prevention of stroke are presented. Specifically, we review the evidence for antiplatelet agents, anticoagulants, antihypertensive medications, lipid-lowering agents and carotid endarterectomy for stroke prevention.

Anticoagulants↗
PubMed2003

Atrial myxoma as a cause of stroke: case report and discussion.

Cardiac myxoma is a source of emboli to the central nervous system and elsewhere in the vascular tree. However, nonspecific systemic symptoms and minor embolic phenomena may be overlooked in the absence of any history of cardiac problems. In this situation, cardiac investigations may not be performed, and diagnosis of this rare condition may be delayed until the onset of more significant embolic disease, such as stroke with functional impairment, as in the case reported here. The clinical presentation of cardiac myxoma is discussed, along with appropriate investigations and treatment, which may prevent such sequelae.

Echocardiography, Transesophageal↗
PubMedDate not supplied

Experience with beta-blockers in long term management of peripartum cardiomyopathy.

Peripartum cardiomyopathy (PPCM) is an ominous complication of pregnancy, about which little is known. Although the role of Beta Blockers is well established in heart failure, there is limited data evaluating their use in Peripartum cardiomyopathy. We report the use of Beta-Blockers (metoprolol) in conjunct with standard heart failure therapy in two patients of PPCM with favorable long-term outcome. Our experience, although limited, highlights the significance of use of Beta-Blockers in this rare life threatening condition.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Review and update of MRI for clinicians.

The goal of this review is to provide clinicians with basic information about MRI and its current available uses. Introductory information and updates about MRI for a broad range of topics are presented: mechanics of MRI, selection of MRI for diagnosis; popular uses of MRI (MRA, acute stroke, acute spinal compression fractures, cardiac MR, breast MR); MR spectroscopy, functional MRI, changes in MRI technology; and MRI safety.

Humans↗
PubMedDate not supplied

Current topics of interest in interventional radiology.

Interventional Radiology utilizes imaging guidance (primarily fluoroscopy, computed tomography and ultrasound) to perform diagnostic and therapeutic procedures in a minimally invasive manner. This update highlights several current and newer interventional radiology options for treatment of uterine fibroids, interventional oncology procedures for liver tumors and metastatic disease, varicose vein treatment, carotid stenting, cerebral aneurysm coiling, and removable inferior vena cava (IVC) filters.

Female↗
PubMedDate not supplied

Diagnostic and therapeutic implications of ST-segment elevation in lead aVR of 12 lead ECG during chest pain.

'aVR' is usually not the preferred lead to diagnose myocardial infarction in clinical settings, it is rather a neglected lead in this context. We describe the case of a 44 year old male who presented with short duration chest pain and ST segment elevation in lead 'aVR'. His left heart catheterization showed left main stem equivalent disease and totally occluded right coronary artery. Patient underwent emergency coronary artery bypass-grafting with favorable outcome. This case highlights the significance of ST segment elevation in lead aVR during chest pain both in diagnosis and management of patients with acute coronary syndrome.

Adult↗
PubMedDate not supplied

Case report congenital LQTS--an electrocardiographic and genotype correlation.

The congenital Long QT Syndrome (LQTS) is characterized by abnormally prolonged ventricular repolarization due to inherited defect in cardiac sodium and potassium channels, which predisposes the patients to syncope, ventricular arrhythmias, and sudden cardiac death. Early diagnosis and preventive treatment are instrumental to prevent sudden cardiac death in patients with the congenital LQTS. The diagnostic criteria for congenital LQTS are based on certain electrocardiographic findings and clinical history. Recently genotype specific electrocardiographic pattern in the congenital LQTS has also been described. Recent studies suggest feasibility of genotype specific treatment of LQTS and in near future, mutation specific treatment will probably become a novel approach to this potentially fatal syndrome. We describe two cases that fulfilled the electrocardiographic and historical diagnostic criteria with morphology on electrocardiogram (ECG) suggestive of LQT1 genotype.

Adult↗